649
FXUS65 KBYZ 130654
AFDBYZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
1254 AM MDT THU AUG 13 2026
KEY MESSAGES
- WIDESPREAD PRECIPITATION IS FORECAST TODAY THROUGH SATURDAY.
LOCALLY HEAVY RAINFALL IS POSSIBLE DURING THIS PERIOD, WITH A
SLIGHT RISK OF EXCEEDING FLOOD GUIDANCE FOR AREAS EAST OF A
ROUNDUP TO BILLINGS TO SHERIDAN LINE.
- TEMPERATURES WILL BE WELL BELOW NORMAL TODAY THROUGH SATURDAY,
AND POSSIBLY SUNDAY.
DISCUSSION
TODAY THROUGH WEDNESDAY...
CONTINUOUS WAVES UNDER SOUTHWEST FLOW ALOFT WILL CONTINUE TO PROVIDE PERIODS OF
SCATTERED TO WIDESPREAD SHOWERS AND THUNDERSTORMS THROUGH SATURDAY. ATMOSPHERIC
MOISTURE WILL CONTINUE TO REMAIN ELEVATED THROUGH SATURDAY WITH PRECIPITABLE
WATER VALUES FROM 1-1.5 INCHES, INCREASING THE RISK FOR HEAVY RAIN. LOOKING TO
THIS AFTERNOON, HI-RES MODELS GENERALLY HAVE SHOWERS AND THUNDERSTORMS MOVING
INTO SOUTHEAST MT THROUGH NORTHEAST WY AND NORTHERN MT LATE
AFTERNOON INTO THE EVENING. THE ENVIRONMENT WILL BE MOST FAVORABLE
FOR A FEW STRONG THUNDERSTORMS EARLY AFTERNOON FOR FAR SOUTHEAST
MT. SCATTERED TO WIDESPREAD SHOWERS AND EMBEDDED THUNDERSTORMS ARE
EXPECTED TO LINGER THROUGH THE OVERNIGHT HOURS AS THE SURFACE LOW
MOVES SLOWLY THROUGH SOUTHEAST MT. INTO FRIDAY AFTERNOON, MODELS
GENERALLY SHOW THE NEXT WAVE BRINGING PRECIPITATION UP THROUGH
SOUTH-CENTRAL MT MID DAY, TRACKING EAST THROUGH THE AFTERNOON AND
EVENING. THE LAST OF THE WAVES PUSHES THROUGH SATURDAY INTO THE
OVERNIGHT HOURS KEEPING LOW TO MODERATE PRECIPITATION CHANCES
ACROSS THE PLAINS WITH HIGH CHANCES FOR AREA MOUNTAINS. THE BEST
PROBABILITIES FOR AT LEAST AN INCH OF PRECIPITATION HAS SHIFTED TO
AREAS WEST OF BILLINGS, CURRENTLY AT A 50-70% CHANCE THURSDAY-
FRIDAY WITH EVEN HIGHER CHANCES FOR THE MOUNTAINS. MODERATE TO
HIGH CHANCES FOR AT LEAST HALF AN INCH EXIST FOR THE REGION AS A
WHOLE FOR THE SAME TIME PERIOD. USE CAUTION IF RECREATING NEAR ANY
BURN SCARS OVER THE NEXT COUPLE DAYS.
HEIGHTS BEGIN TO BUILD BACK IN LATE WEEKEND, BRINGING TEMPERATURES BACK TO NEAR
NORMAL. WITH THE REGION KEEPING A SLIGHT SOUTHWEST FLOW, UNSETTLED CONDITIONS
WILL REMAIN IN PLACE. THIS WILL KEEP LOW TO MODERATE CHANCES FOR AFTERNOON
SHOWERS AND THUNDERSTORMS THROUGH THE PERIOD. PRECIPITABLE WATER VALUES REMAIN
ABOVE AVERAGE (0.75-1 INCH), SO MODERATE TO HEAVY RAINFALL WILL BE LIKELY WITH
THUNDERSTORMS.
HIGH TEMPERATURES WILL BE IN THE UPPER 60S TO LOW 80S THROUGH SATURDAY, WARMING
BACK INTO THE 80S FOR THE REMAINDER OF THE PERIOD. TS
AVIATION
AVIATION
PERIODS OF SHOWERS AND THUNDERSTORMS CAN BE EXPECTED THROUGH THE
PERIOD. THUNDERSTORMS WILL PRODUCE MVFR TO LOCAL IFR REDUCTIONS,
WITH HEAVY RAINFALL AND GUSTY WINDS BEING THE MAIN THREATS. MVFR
TO LOCAL IFR CEILINGS WILL MOVE INTO THE AREA FROM THE NORTHWEST THIS MORNING, PERSISTING THROUGH MID DAY. PATCHY FOG IS POSSIBLE THROUGH EARLY THIS MORNING AS WELL (20% CHANCE), ESPECIALLY WHERE RECENT PRECIPITATION HAS FALLEN.
WILDFIRE SMOKE/HAZE WILL LINGER ACROSS THE REGION AS WELL. IN
CONJUNCTION WITH THE MULTIPLE CLOUD DECKS, EXPECT REDUCTIONS TO
SLANT RANGE VISIBILITY. STP/ARCHER
PRELIMINARY POINT TEMP/POPS
TDY FRI SAT SUN MON TUE WED
-------------------------------------------------------
BIL 076 059/072 055/076 056/082 058/085 058/083 058/083
5/T 77/T 72/T 41/B 11/B 12/T 22/W
LVM 075 049/071 045/076 045/081 047/083 048/081 047/080
4/T 89/T 87/T 62/T 22/T 22/T 23/W
HDN 079 054/074 051/078 051/083 053/087 054/085 054/085
6/T 76/T 64/T 42/W 12/W 22/T 22/W
MLS 079 057/074 053/077 053/082 057/087 058/085 057/084
7/T 85/T 33/W 23/T 23/W 34/T 43/W
4BQ 080 059/075 056/076 055/081 058/086 059/084 059/085
8/T 94/T 63/T 34/T 44/T 43/T 33/W
BHK 077 054/074 049/075 048/080 053/086 054/083 052/083
5/T 88/T 21/E 13/W 33/W 34/T 43/W
SHR 079 053/073 051/073 049/079 050/083 051/082 051/083
8/T 87/T 89/T 62/T 22/T 22/T 22/T
BYZ WATCHES/WARNINGS/ADVISORIES
MT...NONE.
WY...NONE.
WEATHER.GOV/BILLINGS
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